JPH05235862A - Active/standby changeover control system for optical transmitter - Google Patents

Abstract

PURPOSE:To solve the problem that any of both the active/standby systems is not fixed and the system switching is repeated when an optical output is interrupted in the optical transmitter with respect to the optical transmitter having active/standby system transmission lines, especially the active/standby switching control system of the optical transmitter. CONSTITUTION:An active system control section 1 has a 1st optical output interrupt signal section 10 outputting an interrupt signal when an optical output is interrupted, and a standby system control section 2 has an optical output interrupt signal section 20 outputting an interrupt signal when an optical output to a standby transmission line is interrupted. The system is provided with an optical output both system interruption detection section 4 detecting it that the optical output to the active/standby system transmission lines is both interrupted when an interrupt signal is outputted from the optical output interrupt signal section 20. A changeover control section 3 receives the interruption signal from the standby system control section 10 and the optical output from the active system control section 1 is switched into the optical output from the standby system control section 2, and the system is controlled not to be switched when the optical output both system interruption detection section 4 detects that the optical output to the active/standby system transmission lines is both interrupted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical transmission apparatus having a working / standby system transmission line, and more particularly to a working / standby switching control system for an optical transmission apparatus.

[0002]

2. Description of the Related Art FIG. 8 shows a conventional configuration example of a working / spare switching control system, and FIG. 9 is an operation time chart thereof.

In the figure, reference numeral 1 is a control unit for the active system, particularly a part for controlling the optical output to the active transmission line. The control unit 1 outputs an interruption signal when the optical output is interrupted due to a failure of the light emitting element of the active system, etc.
Has 0.

Reference numeral 2 is a control unit of the standby system, particularly a unit for controlling the optical output to the transmission line of the standby system. Similar to the control unit 1, it has an optical output cutoff signal unit 20 that outputs an optical output cutoff signal when the optical output is cut off due to a failure of a light emitting element of the standby system.

Reference numeral 3 denotes a switching system control unit, which has a switching control unit 30 and switches between the active system and the standby system under the control of the monitoring system 4. The monitoring system 4 receives outputs from the control unit 1 of the active system and the control unit 2 of the standby system and controls the switching system 3.

The operation of the conventional example will be described with reference to FIG.

The operation when the optical output of the active system is cut off and the system is switched to the normal standby system is shown in FIG. 9 (1).

When the optical output of the active system is cut off, the optical output disconnection signal of the active system which changes as follows is output from the optical output disconnection signal section 10. This active system optical output interruption signal is guided to the monitoring system 4.

The monitoring system 4 controls the switching control unit 30 to stop the optical output of the active system () and cause the standby system to output the optical output (). As a result, the active system is switched to the standby system. Here, if the standby system is normal, the light output from the standby system is continued ().

On the other hand, if the standby system is abnormal,
As in (2), the output signal from the optical output interruption signal unit 20 of the standby system changes.

This light interruption signal is guided to the monitoring system 4. In the monitoring system 4, since the optical output interruption signal has already been output from the optical output interruption signal section of the working system, this is stored. As a result, the standby system optical output / standby switching signal from the switching system 3 is held as it is (see FIG. 9 (2)).

Therefore, it is not possible to switch back to the active system whose optical output is cut off due to a failure.

[0013]

As described above, in the conventional apparatus, the optical output interruption signal is sent to the monitoring system 4 to switch the system. Further, since the status of the active system is stored, the failure of the active / spare entire system is recognized by this.

Therefore, in such a conventional apparatus, there is a problem that if the monitor system 4 fails, the working / standby main signal system cannot be switched.

Furthermore, if the monitoring system 4 is eliminated and switching is performed, if the optical outputs of both the active system and the standby system are cut off, the system is not fixed and the system switching is repeated.

Therefore, it is an object of the present invention to solve such a problem in the conventional device.

[0017]

FIG. 1 is a principle diagram of a control system of an optical transmission device according to the present invention.

In the figure, 1 is a working system control section for controlling the optical output to the working system transmission path, and 2 is a standby system control section for controlling the optical output to the protection system transmission path. Reference numeral 3 is a switching control unit for switching the optical output from the active system control unit 1 and the standby system control unit 2.

The active system control unit 1 has a first optical output disconnection signal unit 10 which outputs an optical disconnection signal when the optical output to the active transmission line is disconnected. The standby system control unit 2 has a second optical output disconnection signal unit 20 which outputs an optical disconnection signal when the optical output to the standby system transmission line is disconnected.

When an optical disconnection signal is output from the second optical output disconnection signal unit 20 within a predetermined time from the optical disconnection signal output of the first optical output disconnection signal unit 10, the active transmission line and the standby transmission line It has a light output both-system disconnection detection unit 4 that detects that both of the light outputs to the both are disconnected.

Upon receiving the disconnection signal from the first optical output disconnection signal unit 10, the switching control unit 3 switches the optical output from the active system control unit 1 to the optical output from the standby system control unit 2. at the same time,
When the optical output disconnection detection unit 4 detects that the optical outputs to the active transmission path and the standby transmission path are both disconnected, control is further performed so as not to switch the system.

[0022]

When the optical disconnection signal is output from the active system, the state of the optical output of the standby system is detected. Further, a predetermined time is generated from the light interruption signal from the working system, and the state of the light output of the standby system is detected at this time.

In the present invention, as described with reference to FIG. 8, in the conventional example, the light-off signal is guided to the monitoring system 4 to perform the switching control. On the other hand, in the present invention, the state of the standby system at the time when the optical output of the active system is cut off is detected without the use of the monitoring system 4, so that it is possible to switch the system accurately.

[0024]

FIG. 2 shows a first embodiment of an optical transmission apparatus to which the method of the present invention is applied, and FIG. 3 is an operation time chart thereof. Hereinafter, in the description of each drawing, the same or similar parts as those in FIGS. 1, 8 and 9 are designated by the same reference numerals.

In the figure, 1 is a working system control section for controlling the optical output to the working system transmission path, and 2 is a standby system control section for controlling the optical output to the protection system transmission path.

Reference numeral 3 denotes an active system control unit 1 and a standby system control unit 2.
Is a switching control unit for switching the light output from the.

The active system control unit 1 has a first optical output disconnection signal unit 10 which outputs an optical output disconnection signal (FIG. 3A) when the optical output to the active system transmission line is disconnected. There is. Further, it has a time constant circuit 11 for delaying the rising time of the light interruption signal by a predetermined time.

The optical output interruption signal from the optical output interruption signal section 10 is, as shown in FIG. 3A, when the optical output is interrupted during the period in which the system is controlled so as to be the optical output.
The signal level becomes "off". Then, when the system is switched to the standby system, the signal level becomes "normal".

In the time constant circuit 11, only the rising portion of the optical output interruption signal is delayed for a predetermined time. Therefore, the output of the time constant circuit 11 is as shown in FIG.

The optical output disconnection signal (FIG. 3 (1)) from the active system output disconnection signal unit 10 is simultaneously input to the switching control unit 3. The switching control unit 3 outputs the optical output disconnection signal (see FIG. 3 (1)).
3), the active system optical output / standby switching signal is sent to the optical output disconnection signal section 10 as shown in FIG. 3A so as to put the active system in the standby state.

At the same time, the switching control unit 3 sends a standby system optical output / standby switching signal to the standby system optical output disconnection signal unit 20 to bring the standby system into an optical output state, as shown in FIG. ,send.

Here, when the standby system is normal, the optical output continues from the switched standby system. Therefore, the standby system optical output disconnection signal of the optical output disconnection signal unit 20 continues to be in the normal state as shown in FIG. Therefore, the output from the time constant circuit 21 remains unchanged as shown in FIG.

Here, the output of the active system time constant circuit 11 (FIG. 3 (1)) and the output of the standby system time constant circuit 21 (FIG. 3).
(1)) is compared in the optical output both-system disconnection detection unit 4 at the time of determination in FIG. As a result, there is a level difference,
The standby system is judged to be normal, and the system is fixed while being switched to the standby system.

On the other hand, when the standby system is abnormal, that is, when no optical output is obtained from the standby system, the optical output disconnection signal from the standby system optical output disconnection signal 20 is as shown in FIG. ..

Before the switching, it is at the "normal" level, but after the switching, the light output is in the disconnection state due to an abnormality in the standby system, so that it is at the "disconnection" level.

Therefore, since the time constant circuit 21 is a circuit for delaying the rising of the signal, the output of the time constant circuit 21 is the optical output disconnection signal of FIG.
It becomes like FIG. 3 (2).

At this time, the output of the active time constant circuit 11 (FIG. 3 (1)) and the output of the time constant circuit 21 (3 (2))
Means that the levels at the time of judgment are equal, and the optical output disconnection detection unit 4
Determines that the standby system is also abnormal. In this case, since the active system is also in a state where the optical output is cut off, no further switching is performed from the standby system, and the standby system is maintained as it is.

FIG. 4 shows a second embodiment of the optical transmission apparatus to which the method of the present invention is applied, and FIG. 5 is an operation time chart thereof.

The present embodiment is characterized in that the standby system optical output / standby switching signal (FIG. 5 (1)) is delayed by a predetermined time constant.

In the figure, an active system control unit 1, a standby system control unit 2, a switching control unit 3, an optical output disconnection signal unit 10 and an optical output disconnection signal unit 20 are the same as those in the first embodiment of FIG. .. The optical output disconnection signal section 20 is provided with a time constant circuit 22.

When the optical output to the working transmission line is cut off,
An optical output disconnection signal (FIG. 5 (1)) is output from the first optical output disconnection signal unit 10 and input to the switching control unit 3.

The switching control section 3 changes the standby system optical output / standby switching signal which changes as shown in FIG. 5A so that the standby system is switched from the standby state to the output state and the active system is switched to the standby system. Input to the section 20.

Standby optical output / standby switching signal (see FIG. 5)
(1)) is further guided to the standby system time constant circuit 22. The time constant circuit 22 delays the standby system optical output / standby switching signal (FIG. 5 (1)) by a predetermined time and outputs it.

Therefore, the output is as shown in FIG. If the standby system is normal even after being switched from the active system, the signal from the optical output interruption signal unit 20 will be as shown in FIG.
It remains at the "normal" level as in (1).

The optical output disconnection detector 4 includes a time constant circuit 22.
(FIG. 5 (1)) and the signal from the optical output interruption signal unit 20 (FIG. 5 (1)) are compared at the time delayed by the time constant. Since there is no difference in the level of both signals, the standby system is judged to be normal, and the optical output from the standby system is continued.

On the other hand, if the standby system is abnormal, the standby system optical output disconnection signal will be at the "off" level after switching from the active system, as shown in FIG. 5 (2). In this case, since the active system is also in a state where the optical output is cut off, no further switching is performed from the standby system, and the standby system is maintained as it is.

FIG. 6 shows a third embodiment of an optical transmission apparatus to which the system of the present invention is applied, and FIG. 7 is an operation time chart thereof.

In the figure, an active system control unit 1, a standby system control unit 2, and a switching control unit 3 are the same as those in the first and second embodiments.

When the optical output to the working transmission line is cut off,
The optical output disconnection signal (FIG. 7 (1)) output from the first optical output disconnection signal unit 10 changes from the “normal” level to the “off” level. This is input to the switching control unit 3.

The switching controller 3 controls the optical output interruption signal (see FIG. 7).
When (1)) is input, the standby system optical output / standby switching signal shown in FIG. 7A is sent to the standby system optical output disconnection signal section 20 to control the standby system to emit light once.

When the standby system emits light, the light output both system disconnection detection unit 4 determines that the standby system is normal, controls the switching control unit 3, and outputs the active system optical output / standby switching signal (see FIG. 1)
) Is changed from the optical output to the standby level, and the active system is switched to the standby system.

At the same time, the standby system optical output / standby switching signal (see FIG.
(1)) becomes the "light output" level (FIG. 7 (1)) to switch the standby system to the light output state. Therefore, the standby system optical output disconnection signal (FIG. 7 (1)) from the standby system optical output disconnection signal section 20 is kept at the "normal" level so that the standby system continues to output light.

On the other hand, when the standby system is abnormal, the standby system does not emit light even if the light emission is controlled once by the standby system light output / standby switching signal (FIG. 7 (2)). Therefore, once the light emission control is performed, the standby system optical output interruption signal (FIG. 7 (2)) is at the "off" level.

In such a case, switching to the standby system is not performed. Therefore, the active system optical output / standby switching signal (see FIG.
(2)) is still at the level of "optical output", and the standby system optical output / standby switching signal (Fig. 7 (2)) is "standby".
Level continues.

[0055]

As described above, according to the present invention,
When the optical output of the active system is cut off, the state of the standby system is detected at a predetermined time after switching from the active system to the standby system (first and second embodiments). Alternatively, the state of the standby system is detected at a predetermined time before switching to the standby system (third embodiment).

Therefore, when the optical output of the standby system is cut off, in the first and second embodiments, it is fixed to the standby system without being switched back to the active system. Alternatively, in the third embodiment, the active system is fixed as it is without switching from the active system to the standby system.

Due to the features of the present invention, the conventional device,
The problem of the method is that if a failure occurs in the monitoring system, the state of the working system cannot be stored, and therefore the working / standby main signal system cannot be switched. Further, the monitoring system 4 is eliminated and switching is performed. When the optical output is cut off in both the active system and the standby system, the problem that the system is not fixed and the system switching is repeated is solved.

[Brief description of drawings]

FIG. 1 shows the principle of the present invention.

FIG. 2 shows a first embodiment of the present invention.

FIG. 3 shows an operation time chart of the first embodiment in use.

FIG. 4 shows a second embodiment of the present invention.

FIG. 5 shows an operation time chart of a second working example.

FIG. 6 shows a third embodiment of the present invention.

FIG. 7 shows an operation time chart of the third working example.

FIG. 8 shows an example of a conventional device.

FIG. 9 shows an operation time chart of an example of a conventional device.

[Explanation of symbols]

 1 Working system control unit 2 Standby system control unit 3 Changeover control unit 4 Optical output both system disconnection detection unit 10 Working system optical output disconnection signal unit 20 Standby system optical output disconnection signal unit

Claims (4)

[Claims] 1. An active system control unit (1) for controlling an optical output to an active system transmission line, a standby system control unit (2) for controlling an optical output to a standby system transmission line, and the active system control unit. (1) and an optical transmission device having a switching control unit (3) for switching the optical output from the standby system control unit (2), the active system control unit (1) disconnects the optical output to the active system transmission line. Has a first optical output disconnection signal section (10) for outputting a disconnection signal, and the standby system control section (2) outputs a disconnection signal when the optical output to the standby system transmission line is disconnected. A second optical output interruption signal section (20) for outputting the signal, and the second optical output interruption signal section (20) within a predetermined time from the interruption signal output of the first optical output interruption signal section (10). ) Outputs a disconnection signal, the optical output both system disconnection detection unit detects that both the optical outputs to the working transmission line and the standby transmission line are disconnected. 4), and the switching control unit (3) includes the first optical output disconnection signal unit (1
0), the optical output from the active system control section (1) is switched to the optical output from the standby system control section (2), and the optical output both system disconnection detection section (4) When it is detected that the optical outputs to the working transmission line and the protection transmission line are both disconnected, further control is performed so as not to switch the system. / Preliminary switching control method. 2. The method according to claim 1, wherein the disconnection signal is passed through a predetermined time constant circuit (11) for a predetermined time after the first optical output disconnection signal section (10) outputs the disconnection signal. A working / standby switching control method in an optical transmission device, characterized in that the time is delayed by a constant time. 3. The standby system according to claim 1, wherein the switching control section (3) receives the disconnection signal and outputs a predetermined time from the disconnection signal output of the first optical output disconnection signal section (10). The optical output / standby switching signal is passed through the predetermined time constant circuit (21),
A working / standby switching control method in an optical transmission apparatus, wherein the predetermined time constant is delayed. 4. An active system control unit (1) for controlling the optical output to the active system transmission line, a standby system control unit (2) for controlling the optical output to the standby system transmission line, and the active system control unit. (1) and an optical transmission device having a switching control unit (3) for switching the optical output from the standby system control unit (2), the active system control unit (1) disconnects the optical output to the active system transmission line. Has a first optical output disconnection signal section (10) for outputting a disconnection signal, and the standby system control section (2) outputs a disconnection signal when the optical output to the standby system transmission line is disconnected. A second optical output disconnection signal unit (20) for outputting the output signal, and the switching control unit (3) includes the first optical output disconnection signal unit (1).
0), the standby system control unit (2) is controlled to perform temporary optical output, and the output of the second optical output interruption signal unit (20) does not become an interruption signal. If
A working / standby switching control system in an optical transmission device, characterized in that the light output from the working system control unit (1) is switched to the light output from the protection system control unit (2).